yeah, you can't argue with that, Elves seem to be the best, they have a great starting position.
But I disagree about the ballista (specifically against demons)... let the Elf hero pump up Chaos skills, give the ballista enchanted arrows, and the nasty imp will suck up all the mana at the beginning (well, of course, you can shoot them with archers, but then the temptresses will recruit them, or the demonesses will hit hard).
Regarding the Elf's Stronghold... it's fun to constantly rely on luck, and you'll have to develop skills properly. But then you'll have to forget about the Elf's special ability or cast Divine Retribution on the arrow if it's available (unlikely).